The present invention relates to communications and in particular to a method and system for passing information and caller identification between independent parties over a public switched telephone network.
Public switched telephone networks (PSTNs) have been commonly used to establish telephone calls between communicating parties. With the advent of modems, PSTNs have also been used to allow electronic equipment at remote sites, such as for example, security panels, vending machines, environment monitoring systems, meters, and load management systems, to send information to a central location or clearing house.
Currently, in the latter case, when electronic equipment at a remote site is to send information to the central location, the modem at the remote site, goes off-hook and dials the telephone number assigned to the central location. When the call is answered, the electronic equipment at the remote site sends the information electronically over the PSTN to the central location. Once the information has been sent, the modem at the remote site hangs up to terminate the call.
Typically, the central location receives information from electronic equipment at a significant number of remote sites. Often, a plurality of remote sites call into the central location at the same time. In order to handle multiple calls, the central location is connected to the PSTN via a number of telephone lines, each having an associated modem and telephone number. If a modem at a remote site dials the telephone number assigned to one of the modems at the central location and a busy signal is received, the modem at the remote site hangs up and tries the telephone number assigned to another one of the modems.
In some countries, call charges apply whenever a remote modem makes a connection with a modem at a central location. Also, long-distance charges may apply if the central location is situated in a different geographical location than the remote site initiating the call. Even though electronic equipment at remote sites often send short information messages, telephone charges can still be substantial if the messages are sent on a regular basis, and especially if the messages are sent over a wireless communication network.
Security systems for both residential and commercial applications have gained wide acceptance and central monitoring of such security systems is typically recommended. As a result, many security systems connect to a central monitoring station over a PSTN when an alarm condition arises to relay the alarm information to the central monitoring station.
Security systems of this nature typically include a number of sensors to monitor the area under surveillance. The sensors communicate with an on-site alarm panel that acts as a central source for the sensors. The alarm panel connects to the central monitoring station over a PSTN when an alarm condition occurs, and relays the sensor information to the central monitoring station. The central monitoring station in turn processes the sensor information and based on the processed information, takes or initiates certain predetermined steps. These steps may include producing an operator report and/or contacting the local police department, fire department or private security personnel. Of course, the steps to take in response to sensor information can vary depending on the needs of the customer, the owner of the alarm panel and/or the assessment of the alarm condition made by the operator at the central monitoring station.
In modern PSTNs, caller line identification (CLI) data is often transmitted to locations receiving incoming calls. CLI data is particular to each subscribed telephone service and typically contains the telephone number of the calling party, alpha-numeric identification of the calling party, and the time and date of the call. Of course, other information may also be provided. Security systems, which use CLI data accompanying a call, have been considered.
For example, U.S. Pat. No. 5,511,109 to Hartley et al discloses a security system using call display. The security system includes a plurality of alarm panels, each of which is associated with a plurality of sensors. The alarm panels are connected to a PSTN via telephone lines. A receiving arrangement is connected to the PSTN and recognizes calls generated by the alarm panels. The receiving arrangement is also connected to a central computer. When an alarm panel generates a call in response to an alarm condition as detected by one or more of its associated sensors, the PSTN supplies CLI data identifying the calling alarm panel. The receiving arrangement in turn answers the call allowing the alarm panel to send alarm information to the central computer. The CLI data supplied by the PSTN together with the alarm information received from the alarm panel is used by the central computer to determine the steps to take in response to the alarm condition. Unfortunately, this security system can be costly to customers if long distance telephone charges apply to the call made by the alarm panel or if the call made by the alarm panel is carried out over a wireless communication network where airtime charges apply.
Canadian Patent Application No. 2,214,525 to Drysdale et al discloses a system for monitoring the integrity of a telephone connection between an alarm system and a central location established over a PSTN. The alarm system includes a digital communicator for establishing a call to the central location at predetermined intervals or in response to polls made by the central location. If no alarm condition exists when a call is to be made to the central location, the digital communicator drops the call after CLI data has been transmitted to the central location. This allows the central location to confirm the integrity of the telephone connection to the alarm system without having to answer the call. If an alarm condition exists when a call is to be made to the central location, the digital communicator maintains the call. When the call is answered by the central location, alarm information is transmitted to the central computer. As will be appreciated, during an alarm condition, a telephone call is established between the alarm system and the central location. Thus, long distance telephone charges may apply to the call made by the alarm system. Also, if the call made by the alarm system is carried out over a wireless network, airtime charges may apply.
Furthermore, regulations often require security systems to be tested on a regular basis. In the case of the Hartley et al and Drysdale et al systems described above, this requires a telephone connection to be established between the alarm systems and the central locations. If long distance charges apply or if wireless communication network airtime charges apply, costs are added to the ownership of the alarm systems.
It is therefore an object of the present invention to obviate or mitigate the above-identified disadvantages.
According to one aspect of the present invention there is provided a monitoring station to monitor the status of at least one remote site over a public switched telephone network (PSTN), said monitoring station comprising:
a plurality of call receiving interfaces to receive calls from said at least one remote site over said PSTN and accompanying caller identification data, each call receiving interface having a telephone number corresponding to specific information to be conveyed from said at least one remote site to said monitoring station; and
a processor in communication with said call receiving interfaces, said processor receiving call receiving interface identification data and caller identification data in response to calls received by said call receiving interfaces to allow said processor to receive specific information from said at least one remote site and its identity without requiring said call receiving interfaces to answer the calls.
Preferably, the caller identification data is caller line identification (CLI) data generated by the PSTN. In one embodiment, the at least one remote site includes a plurality of sensors, each of the sensors being assigned a unique number. In this case, selected call receiving interfaces have telephone numbers incorporating the numbers of particular sensors so that calls received by each selected call receiving interface from the at least one remote site in response to sensor output, identify the sensor responsible for the calls. CLI data accompanying the calls identifies the location of the sensors.
In another embodiment, the at least one remote site includes at least one meter for measuring a utility consumption and storing a meter reading. In this case, selected call receiving interfaces have telephone numbers with digits representing digits of the meter reading and digit values so that calls received by selected call receiving interfaces from the at least one remote site identify meter reading digits and values. CLI data accompanying the calls identifies the location of the at least one meter.
Prefereably, the processor polls a database storing information concerning actions to be performed in response to calls received by the call receiving interfaces. In one form, the processor is a computer. The monitoring station further includes a display coupled to the computer for displaying CLI data received from the call receiving interfaces as well as information read from the database. It is also preferred that the monitoring station further includes a printer coupled to the computer for printing the CLI data and information read from the database in response to calls received from the call receiving interfaces.
According to another aspect of the present invention there is provided a system for communicating information and caller identification between entities over a public switched telephone network (PSTN) comprising:
at least one remote site including a device whose status is to be monitored, said remote site being coupled to said PSTN and being operable to make a call when the device status is to be determined; and
a monitoring station including a plurality of call receiving interfaces coupled to said PSTN and a processor coupled to said call receiving interfaces, each call receiving interface being assigned a different telephone number corresponding to information concerning the status of said device, each call receiving interface conveying caller identification data received from said PSTN and call receiving interface identification data to said processor in response to a call received from said remote site over said PSTN to allow said processor to determine the status of said device and its location without requiring said call to be answered.
According to still yet another aspect of the present invention there is provided a method for monitoring the status of a device at a remote location over a public switched telephone network (PSTN) comprising the steps of:
determining the status of said device and using the status to generate a telephone number;
dialing said telephone number to make a call over said PSTN, said telephone number corresponding to a specific call receiving interface of a monitoring station;
dropping the call after a sufficient number of ringing signals have been received by said specific call receiving interface to ensure deliver of caller identification data to said call receiving interface by said PSTN; and
processing the caller identification data and call receiving interface identification data to determine the location and status of said device without requiring the call to be answered.
According to still yet another aspect of the present invention there is provided a method for conveying the status of a device at a remote location over an Internet connection to a monitoring station comprising the steps of:
determining the status of said device at said remote location and using the status to generate an electronic mail (e-mail) address leader;
generating an e-mail address by appending said leader to the site address assigned to said monitoring station;
dispatching an e-mail message to said monitoring station including said e-mail address and a return address assigned to said remote location; and
processing the e-mail message by examining the e-mail address leader to determine the status of said device and the return address to determine the location of said device.
The present invention provides advantages in that information can be sent and received between entities over a PSTN with incurring long distance or airtime charges. In addition, information can be transmitted over an Internet connection in an manner which limits the amount of power and memory required to process the information.